The biggest cause of failure in hvac systems is a bad compressor. For some reason the contractors always talk the customer into buying a whole new system. On my block people have been spending 9 to 12k.
If it is a compressure failure than no need to replace the whole condenser. Just replace the compressor. With parts and labor it shouldn't cost more than $2500. Everything else on the condenser unit is relatively cheap to fix and is an easy DIY repair. There are many YouTube videos that explain how.
But to extend the life of compressor for many more years, add a soft start.
https://www.youtube.com/watch?v=MDp1g8r8IVs